Apparatus for compacting earth



March 12, 1963 v. T. CALFEQE 3,080,799

APPARATUS FOR COMPACTING EARTH Filed March 26, 1959 5 Sheets-Sheet 1 l6 /4 FIG.

INVENTOR. V/RG/L 7. CALFEE Mo Md/QL AGENT March 12, 1963 v. T. CALFEE 3,080,799

APPARATUS FOR COMPACTING EARTH Filed March 26; 1959 3 Sheets-Sheet 2 l o OIl cn O cu m a: a; a:

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0 o (DOCDI Do| a; col 0 Q I {D E0 Q 11F I] (D V 2 28 FIG. 6 INVENTOR. VIRGIL 7'. CALFEE AGENT March 12, 1963 v. -r. CALFEE APPARATUS FOR COMPACTING EARTH 3 Sheets-Sheet 3 Filed March 26, 1959 FIG.

INVENTOR.

V/RGIL T. CALFEE FIG.H

wz uw 91. AGENT 3,080,799 APPARATUS FOR CGMPACTING EARTH Virgil T. Calfee, Dallas, Tex., assignor of one-sixth each to Rudolph E. Hilrel, Waco, Tex., Ernest J. Behringer,

Waco, Tex., William E. Halstead, Dallas, Tex., Edward H. Small, Dallas, Tex., and Thomas D. Copeland, Jr.,

Garland, Tex.

Filed Mar. 26, 1959, Ser. No. 802,255 Claims. (Cl. 9450) This invention relates generally to earth working machinery and more particularly to that type of equipment known in the trade as Sheeps Foot Rollers and used for tamping or compacting the surface of the earth preparatory to forming a roadway, air strip, building foundation or other construction purpose.

One object of this invention is to provide a sheeps foot roller assembly, which will contain a greater plurality of tamping feet than is possible with conventional rollers of an equivalent size.

A primary object of this invention is to provide a sheeps foot roller assembly which is capable of making more tamping passes at any forward vehicle speed than is possible using conventional rollers of any size.

Another object is to .provide a device which combines the foot spacing advantages of a small diameter sheeps foot roller with the additional weight advantages of a large diameter roller.

A further object is to provide a novel drive system whereby the rotating movement of the sheeps foot rollers across the surface of the earth will be power driven instead of merely being towed as in the prior art.

An additional object and advantage of this invention is to provide a novel cleaning arrangement whereby the rotary movement of the rollers provide movement necessary to dislodge rocks or mud which have become embedded in the space between adjacent tamping feet.

A further object of a modified embodiment of this invention is to provide a unique power driven mud cleaning arrangement for a sheeps foot roller of this type.

Another object is to provide an improved method of compacting soil which includes making several passes of tamping means across each successive segment of the surface of the earth as the compacting apparatus travels forward.

A further object of this invention is to provide a method which will permit a segment of the earths surface to be compacted in sheeps foot roller fashion without the ne cessity of the compacting apparatus having any travel movement.

Another object is to provide a means whereby sheeps foot roller tamping action may be applied to the earths surface from a stationary apparatus.

An additional object is to provide an apparatus for tamping the earths surface which employs a plurality of power driven orbital moving sheeps foot rollers.

And yet another object is to provide a modified version of the apparatus of this invention in which a plurality of power driven orbital moving sheeps foot rollers are combined with a large central drum whereby the weight of the drum will provide additional compacting weight for each roller when it occupies its lowermost tamping position.

And still a further object is to provide a sheeps foot roller assembly which is composed of a plurality (greater than two) of individual tamping rollers which are journalled in a spider wheel which is itself power driven to rotate about a center axis and impart a rearward speed to the rollers that are in contact with the ground that exceeds the forward speed of the towing vehicle.

And another object is to provide a sheeps foot roller assembly which the tamping feet in contact with the ground are forced into the soil by applied power rather than by the roll due to towing action.

A further object is to provide a sheeps foot roller assembly which combines the sheeps foot tamping action with an impact force when each individual roller of the assembly engages the ground.

Another object is to provide a sheeps foot roller assembly in which the direction of rotation of the tamping feet is exactly opposite from present day sheeps foot rollers; which action will cause loose dirt and mud to be thrown in the path of other tamping feet so that a cleaner worked surface will be left after the roller has passed by.

And an object of this invention is also to provide a sheeps foot roller assembly in which several tamping foot rollers are provided with feet arrangement and spacing such that the entire road surface will be compacted and not just the spaced location of tamping feet.

Another object is to provide a sheeps foot roller assembly which includes means by which the tamping action is controlled by th eoperator and is a function of the variable ratio of the forward speed of the tractor to the axial rotation of the roller assembly.

An additional object is to provide a sheeps foot roller assembly in which additional cleaning action may be imparted to the assembly by increasing the centrifugal force at the tamping foot surface to sling off any mud lodged between the feet.

And yet another object is to provide a sheeps foot roller assembly in which a fewer number of tamping feet are in contact with the ground than on single drum rollers of the same weight so that an increased tamping density per foot is obtained, and an assembly in which the weight may be greatly increased without appreciably increasing this instantaneous contact area of the feet and the ground.

These and other objects and advantages will be apparent from an examination of the specification and drawings in which:

FIG. 1 represents an elevational view of a four drum sheeps foot roller assembly of this invention.

FIGS. 2-4 are outline diagrammatic views showing the method employed in this invention to compact the earth.

FIG. 5 is an elevational view of a six drum sheeps foot roller assembly of the invention.

FIG. 6 is a plan view of the device shown in FIG. 5.

FIG. 7 is a fragmentary detail view of the modified foot cleaning device shown in FIG. 8.

FIG. 8 is an elevational outline view of a three drum sheeps foot roller assembly with the spider frame and draft frame removed to show the power driven cleaning assembly employed.

FIG. 9 is an enlarged detail of the cleaning device of FIG. 7.

FIG. 10 is a plan view of the center section of FIG. 8, showing its structural detail.

FIG. 11A is a plan view of the earth showing the tamping foot spacing imprinted in the earth after a conventional drum type sheeps foot roller has passed thereover.

KG. 1113 is a plan view of the same segment of the earth as shown in FIG. 11A after the orbital sheeps foot roller assembly of this invention has passed thereover.

Referring now more particularly to the characters of reference in the drawing it will be observed that the sheeps foot roller assembly of this invention is identified generally at 2 in FIG. 1. The assembly 2 includes basically a draft frame 3 having a ball joint 4 which swivelly connects the assembly 2 with a towing vehicular on tractor 5.

The draft frame 3 is U-shaped and extends along each lateral side of the assembly so as to provide bearing support for the main axle 6 which may be a single shaft axle,

to which one or more pulleys 7 and spider frames 8 are rigidly attached. The complete drive means, identified generally at 9, includes an auxiilary power unit 9A (shown here as an electric motor), a drive pulley 19 mounted on the frame 3 and in power driving relation with the pulley 7, and a drive belt 11. Alternately, the drive means may include any known power medium such as P.T.O. (power-take-off) unit, hydraulic motor, gasoline engine, etc., and any satisfactory power transfer element such as V-belt, sprocket belt, chain, cable, etc. The important construction here is that the power drive means be capable of rotating the spider frame without slipping and it is desirable that this frame will rotate in such a direction (i.e., clockwise in FIGS. 1-5) that the ground engaging sheeps foot rollers 12 move rearwardly at a ground speed which exceeds the fastest operational forward speed of the tractor. v

A plurality of orbital spaced individual sheeps foot rollers 12 are journalled to the ends of the spider frame arms at bearings 13. Each roller 12 is free to rotate in the spider 8 but its tendency is to not rotate until its feet 14 are in engaging contact with the ground G. With the assembly 2 in the position shown in FIGS. 1 and 2, operation of the power means 9 will cause the spider frame to rotate clockwise and the tamping feet 14 will sequentially engage the ground as their roller moves about its axis in a counterclockwise rotation. When the first roller 12 has moved rearward until it has reached the position shown in FIG. 3, the next roller 12' is moving toward the earth at a relatively rapid speed. When the roller 12' has actually impacted the earth as shown in FIG. 4, both rollers 12 and 12' will be rotating about their individual axes for the first time and this condition will continue for only a short period of time until frame 8 has lifted the roller 12 off the ground.

The main axle 6 will rise and fall during the rotation of frame 8 without interference from any of the remaining structure of the assembly since draft frame 3 is journalled to the main axle 6 and swivel connected to the tractor at 4.

The fact that the individual sheeps foot rollers 12 are smaller in diameter than a single drum of an equivalent weight of the assembly 2 will permit the tamping feet 14 to be spaced much closer together and yet have fewer feet in actual contact with the ground. This is desirable since it increases the loading on each foot and this increases the compacting action into the soil.

In FIG. 1 the cleaning device indicated at 15 is in the form of a continuous chain 16 which overlays each of the four rollers snugly but is not rigidly attached to any roller. While the preferred form of the chain 16 is shown in solid to loop about all four rollers, a modified form of this loop is shown in phantom lines at 16' which overlays only two of the drums. The closed loop formed by chain 16 is ideal where the corresponding foot spacing of all the rollers coincide in the same vertical plane, or if the foot spacing is staggered the chain 16 may be employed if the distance between the rollers permits a slight angling of the chain when passing from one roller to the next. For small dimensions and where the foot spacing of each roller is staggered from the preceding roller, the closed loop shown 'by chain 16 may be employed between diametrically opposed rollers 12. A second chain 16' may then be looped between the other two rollers 12' in such a manner that it will be at right angles to the first chain 16' and will engage the open spacing between the feet at a staggered axial distance from the foot spacing engaged by the first chain 16'. When both rollers 12 and 12 are in contact with the ground as shown in FIG. 1, the chain 16 will not itself come into contact with the ground during normal operation but there will be relative motion between the chain 16 and any rollers 12 and 12 which are in contact with the ground.

Referring now to FIG. 5, it will be observed that the sheeps foot roller assembly 20 includes a spider frame 28 pivotally supported by a draft frame 23 which is also adapted to be swivelly attached at 4 to a tractor 5. This assembly is similar to the assembly shown in FIG. 1, except that it includes six individual orbital moving drum type sheeps foot rollers 22 and a central drum 40 which is rigidly attached to a center axle 26 and to a driven sprocket 27. This embodiment shows an electric motor 29 in driving relation to a drive means 30 including reducing gears 41 on the same shaft 42 as the driving sprocket 43 which, through chain 44 rotates the driven sprocket 27. Alternatively, the electric motor 29 may be replaced by a power take-off unit shown in phantom at 45 which is powered mechanically from the tractor 5 in a well known manner. A unique foot cleaning means 46 has been in stalled on the assembly 20 in the form of a link chain 47 which is anchored at 48 to the central drum 49. With both ends of the chain thus anchored the chain loops about the circumference of the rollers 22 and drags off any mud or rocks wedged in the spacing between feet whenever there is relative motion between the rollers 22 and the chain 47. This latter event occurs as soon as the feet 24 of a particular roller come into contact with the ground and continues as long as any feet of that roller engage the ground.

In FIG. 6 is it seen how the feet of adjacent rollers are staggered laterally so that they will not follow in the same tracks of the preceding roller and will thus provide total compacting coverage to a surface of the earth with only one pass over the surface of the towing tractor 5. Since the individual rollers 22 are free to rotate with their stub shafts 4-9 in their bearings 50 on the spider frame 28, the individual feet 24 will also have no tendency to track in previously compacted tracks in the direction of travel. A valid comparison may be seen between the spaced impact of the tracks 51 of a conventional drum type sheeps foot roller shown in FIG. 11A and the overlapping impact of the tracks 2 of the orbital type sheeps foot roller assembly of this invention as shown in FIG. 1113.

Reference to FIGS. 7-10 will disclose the unique power driven cleaner means 60 of a modified embodiment of the invention. While one basic requirement of the instant invention is merely that a plurality of rollers radially spaced from a central orbit are caused to rotate about the orbit by a force independent of the speed of the towing vehicle, yet from a practical standpoint the number of such rollers will probably be at least three as shown in outline form in FIG. 8. The individual rollers 22 of this embodiment 69 are equally radially and angularly spaced about a center axis as indicated at shaft assembly 61. A series of disks 62 are axially spaced along the shaft 6 and rigid thereto as seen in FIG. 10, and a sprocket 64 is also rigidly attached to the shaft in the intervals between the disks to complete the shaft assembly 61. Each sprocket 64 meshes with a drive chain 65 which is reeved over the top of one of the rollers 24 and under the remaining two and thence over the sprocket 64 to complete a power driven chain cleaning assembly. As the spider frame (not shown) of FIG. 8 revolves, the closed loop chain 65 becomes power driven relative to the individual rollers 22. Any of the cleaning means described, and cable 65A in particular, may include a series of fiippers 66 as shown in FIGS. 7 and 9. As the chain or cable 65A passes or is driven through the space between the feet 24, the individual flippers 66, being pivoted at 67 is the cable 65A, will be spun by each foot 24 they come into contact with and their length may exceed the foot spacing if desired so they will actually hit every foot in sequence and create a considerable churning action which will dislodge any mud or the like which is embedded between the feet.

From the foregoing description it will be readily seen that there has been produced a device which substantially fulfills the objects of the invention as set forth herein. The invention is not limited to the exemplary constructions herein shown and described, but may be made in many ways within the scope of the appended claims.

What is claimed is: v I 1. A sheeps foot roller assembly adapted to be drawn by a towing vehicle, comprising:

(a) a draft frame,

(b) a transverse central axle supported by said draft frame,

(0) a pair of spider frames each having a plurality of radiating arms of substantial length each forming a substantial angle with the next adjacent arm and each spider frame supported by said central axle at each lateral end of said axle and rotatable about the axis of said axle,

(d) a roller shaft extending between each corresponding pair of said radiating arms,

(e) a sheeps foot roller attached to each roller shaft and being rotatable about the axis of said shaft,

(7) each roller extending substantially the full width of said draft frame,

(g) drive means on said draft frame connected to each said spider frame in operating relation thereto for rotating said arms and said attached rollers in a rotary path,

(12) and a plurality of tamping feet on each sheeps foot roller and so positioned on each of said rollers to completely perforate the entire surface being tamped,

(i) the length of said arms and sheeps foot roller diameter being effective to produce a difference in height of said central axle from the surface being tamped by raising said axle when one roller is in contact with the surface being tamped from a lowered position when two rollers are in contact.

2. A sheeps foot roller assembly as in claim 1 wherein each of said spider frames have at least three arms.

3. A sheeps foot roller assembly adapted to be drawn by a towing vehicle, comprising:

(a) a draft frame, (b) a transverse central axle supported by said draft frame,

(c) a pair of spider frames each having a plurality of radiating arms of substantial length each forming a substantial angle with the next adjacent arm and each spider frame supported by said central axle at each lateral end of said axle and rotatable about the axis of said axle,

(d) a roller shaft extending between each corresponding pair of said radiating arms,

(e) a sheeps foot roller attached to each roller shaft and being rotatable about the axis of said shaft,

(f) each roller extending substantially the full width of said draft frame,

(g) drive means on said draft frame connected to each said spider frame in operating relation thereto for rotating said arms and said attached rollers in a rotary path,

(h) a plurality of tamping feet on each sheeps foot roller,

(1) continuous cleaning means in direct contact with and passing around a portion of the periphery of at least one of said rollers.

4. A sheeps foot roller assembly as in claim 3, wherein said cleaning means includes a chain as the continuous means.

5 A sheeps foot roller assembly as in claim 3, wherein said cleaning means includes a cable as the continuous means.

References (Iited in the file of this patent UNITED STATES PATENTS 

1. A SHEEP''S FOOT ROLLER ASSEMBLY ADAPTED TO BE DRAWN BY A TOWING VEHICLE, COMPRISING: (A) A DRAFT FRAME, (B) A TRANSVERSE CENTRAL AXLE SUPPORTED BY SAID DRAFT FRAME, (C) A PAIR OF SPIDER FRAMES EACH HAVING A PLURALITY OF RADIATING ARMS OF SUBSTANTIAL LENGTH EACH FORMING A SUBSTANTIAL ANGLE WITH THE NEXT ADJACENT ARM AND EACH SPIDER FRAME SUPPORTED BY SAID CENTRAL AXLE AT EACH LATERAL END OF SAID AXLE AND ROTATABLE ABOUT THE AXIS OF SAID AXLE, (D) A ROLLER SHAFT EXTENDING BETWEEN EACH CORRESPONDING PAIR OF SAID RADIATING ARMS, (E) A SHEEP''S FOOT ROLLER ATTACHED TO EACH ROLLER SHAFT AND BEING ROTATABLE ABOUT THE AXIS OF SAID SHAFT, (F) EACH ROLLER EXTENDING SUBSTANTIALLY THE FULL WIDTH OF SAID DRAFT FRAME, (G) DRIVE MEANS ON SAID DRAFT FRAME CONNECTED TO EACH SAID SPIDER FRAME IN OPERATING RELATION THERETO FOR ROTATING SAID ARMS AND SAID ATTACHED ROLLERS IN A ROTARY PATH, (H) AND A PLURALITY OF TAMPING FEET ON EACH SHEEP''S FOOT ROLLER AND SO POSITIONED ON EACH OF SAID ROLLERS TO COMPLETELY PERFORATE THE ENTIRE SURFACE BEING TAMPED, (I) THE LENGTH OF SAID ARMS AND SHEEP''S FOOT ROLLER DIAMETER BEING EFFECTIVE TO PRODUCE A DIFFERENCE IN HEIGHT OF SAID CENTRAL AXLE FROM THE SURFACE BEING TAMPED BY RAISING SAID AXLE WHEN ONE ROLLER IS IN CONTACT WITH THE SURFACE BEING TAMPED FROM A LOWER POSITION WHEN TWO ROLLERS ARE IN CONTACT. 